1. Field of the Invention
The present invention relates to a crossed-field amplifier and, more particularly, to a bias circuit and method used within a crossed-field amplifier to reduce amplifier jitter caused by stopping and restarting the amplifier.
2. Description of the Prior Art
Crossed-field amplifiers have been known for several years. These amplifiers are typically utilized in electronic systems which require high voltages, such as radar systems. Typically the cathode of a crossed-field amplifier is operated at a high negative voltage. Such high voltages generate heat which may be reduced by a liquid cooling system. An example of a crossed-field amplifier which is liquid cooled is shown in U.S. Pat. No. 4,700,109, issued Oct. 13, 1987, by G. R. MacPhail, which is assigned to the common assignee.
In some applications, it is desirable to switch crossed-field amplifier on and off so as to reduce the amount of electro-magnetic energy radiated from an electronic system within which the crossed-field amplifier is used. This feature is desirable if, for example the amplifier were utilized within a radar system on board a ship where excessive radiation of electromagnetic energy could be utilized to identify the ship's location.
A crossed-field amplifier, however, has difficulty restarting after it has been turned off. That is, at lower pulse repetition frequencies the amplifier will not start quickly enough to pass the stringent specifications set for it or the system in which it is used.